1. Field of the Invention
The present invention relates to a facsimile apparatus, and more particularly to a facsimile apparatus having an error resend mode.
2. Related Background Art
As a facsimile apparatus having an error resend mode, a facsimile apparatus having an error correction mode (ECM) by a half-duplex communication by the CCITT Recommendation has been known. In a normal telephone line, a probability of occurrence of a transmission error is high and a portion of the image information is lost by the transmission error, but an image may be received without transmission error by transmitting the image by the ECM communication.
In the prior art G3 standard facsimile apparatus, the Modified Huffmann (MH) encoding system or the Modified Read (MR) encoding system has been adopted in order to reduce an affect by the effect of transmission error. However, in the ECM communication, a two-dimensional compression encoding system having a higher compression factor than that of the MH or MR encoding system, for example, the Modified Modified Read (MMR) encoding system, may be adopted in order to reduce the amount of image information to be transmitted to improve a transmission efficiency.
In the ECM communication, the image information which included a transmission error is resent. However, depending on a line condition, a normal image (error-free image) may not be obtained even if the error portion is repeatedly resent. If the MMR code is adopted, the information following the error portion on the page is regarded as an error and it is lost when the error portion is left.
Accordingly, when the ECM communication is effected with the MMR code, the communication is effected in vain when the error portion is left on the page and the rest of the page is sent by the ECM communication.
Patents and patent applications relating to the error resend include U.S. Pat. No. 4,829,524, U.S. Pat. No. 4,885,755, Ser. No. 352,830 (filed on May 16, 1989), Ser. No. 267,541 (filed on Nov. 4, 1988), Ser. No. 337,152 (filed on Apr. 12, 1989) and Ser. No. 371,847 (filed on Jun. 27, 1989), but none of them proposes a solution to the above-mentioned problems.